ArrayList.GetRange(Int32, Int32) Metodo

Definizione

Restituisce ArrayList che rappresenta un subset di elementi nell'oggetto ArrayList di origine.Returns an ArrayList which represents a subset of the elements in the source ArrayList.

public:
 virtual System::Collections::ArrayList ^ GetRange(int index, int count);
public virtual System.Collections.ArrayList GetRange (int index, int count);
abstract member GetRange : int * int -> System.Collections.ArrayList
override this.GetRange : int * int -> System.Collections.ArrayList
Public Overridable Function GetRange (index As Integer, count As Integer) As ArrayList

Parametri

index
Int32

Indice in base zero di ArrayList in corrispondenza del quale inizia la serie.The zero-based ArrayList index at which the range starts.

count
Int32

Numero di elementi nell'intervallo.The number of elements in the range.

Restituisce

ArrayList

Oggetto ArrayList che rappresenta un subset di elementi nell'oggetto ArrayList di origine.An ArrayList which represents a subset of the elements in the source ArrayList.

Eccezioni

index è minore di zero.index is less than zero.

-oppure--or- count è minore di zero.count is less than zero.

index e count non indicano un intervallo valido di elementi nell'oggetto ArrayList.index and count do not denote a valid range of elements in the ArrayList.

Esempio

Nell'esempio di codice seguente viene illustrato come impostare e ottenere un intervallo di elementi in ArrayList .The following code example shows how to set and get a range of elements in the ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList, char mySeparator );
int main()
{
   
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "The" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   
   // Creates and initializes the source ICollection.
   Queue^ mySourceList = gcnew Queue;
   mySourceList->Enqueue( "big" );
   mySourceList->Enqueue( "gray" );
   mySourceList->Enqueue( "wolf" );
   
   // Displays the values of five elements starting at index 0.
   ArrayList^ mySubAL = myAL->GetRange( 0, 5 );
   Console::WriteLine( "Index 0 through 4 contains:" );
   PrintValues( mySubAL, '\t' );
   
   // Replaces the values of five elements starting at index 1 with the values in the ICollection.
   myAL->SetRange( 1, mySourceList );
   
   // Displays the values of five elements starting at index 0.
   mySubAL = myAL->GetRange( 0, 5 );
   Console::WriteLine( "Index 0 through 4 now contains:" );
   PrintValues( mySubAL, '\t' );
}

void PrintValues( IEnumerable^ myList, char mySeparator )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::Write( "{0}{1}", mySeparator, obj );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 Index 0 through 4 contains:
         The     quick   brown   fox     jumps
 Index 0 through 4 now contains:
         The     big     gray    wolf    jumps
 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );

      // Creates and initializes the source ICollection.
      Queue mySourceList = new Queue();
      mySourceList.Enqueue( "big" );
      mySourceList.Enqueue( "gray" );
      mySourceList.Enqueue( "wolf" );

      // Displays the values of five elements starting at index 0.
      ArrayList mySubAL = myAL.GetRange( 0, 5 );
      Console.WriteLine( "Index 0 through 4 contains:" );
      PrintValues( mySubAL, '\t' );

      // Replaces the values of five elements starting at index 1 with the values in the ICollection.
      myAL.SetRange( 1, mySourceList );

      // Displays the values of five elements starting at index 0.
      mySubAL = myAL.GetRange( 0, 5 );
      Console.WriteLine( "Index 0 through 4 now contains:" );
      PrintValues( mySubAL, '\t' );
   }

   public static void PrintValues( IEnumerable myList, char mySeparator )  {
      foreach ( Object obj in myList )
         Console.Write( "{0}{1}", mySeparator, obj );
      Console.WriteLine();
   }
}


/*
This code produces the following output.

Index 0 through 4 contains:
        The     quick   brown   fox     jumps
Index 0 through 4 now contains:
        The     big     gray    wolf    jumps
*/
Imports System.Collections

Public Class SamplesArrayList

    Public Shared Sub Main()

        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")

        ' Creates and initializes the source ICollection.
        Dim mySourceList As New Queue()
        mySourceList.Enqueue("big")
        mySourceList.Enqueue("gray")
        mySourceList.Enqueue("wolf")

        ' Displays the values of five elements starting at index 0.
        Dim mySubAL As ArrayList = myAL.GetRange(0, 5)
        Console.WriteLine("Index 0 through 4 contains:")
        PrintValues(mySubAL, vbTab)

        ' Replaces the values of five elements starting at index 1 with the values in the ICollection.
        myAL.SetRange(1, mySourceList)

        ' Displays the values of five elements starting at index 0.
        mySubAL = myAL.GetRange(0, 5)
        Console.WriteLine("Index 0 through 4 now contains:")
        PrintValues(mySubAL, vbTab)

    End Sub

    Public Shared Sub PrintValues(myList As IEnumerable, mySeparator As Char)
        Dim obj As [Object]
        For Each obj In  myList
            Console.Write("{0}{1}", mySeparator, obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class


' This code produces the following output.
' 
' Index 0 through 4 contains:
'         The     quick   brown   fox     jumps
' Index 0 through 4 now contains:
'         The     big     gray    wolf    jumps

Commenti

Questo metodo non crea copie degli elementi.This method does not create copies of the elements. Il nuovo ArrayList è solo una finestra di visualizzazione nell'origine ArrayList .The new ArrayList is only a view window into the source ArrayList. Tuttavia, tutte le modifiche successive apportate all'origine ArrayList devono essere eseguite tramite questa finestra di visualizzazione ArrayList .However, all subsequent changes to the source ArrayList must be done through this view window ArrayList. Se le modifiche vengono apportate direttamente all'origine ArrayList , la finestra di visualizzazione ArrayList viene invalidata e tutte le operazioni su di essa restituiranno un InvalidOperationException .If changes are made directly to the source ArrayList, the view window ArrayList is invalidated and any operations on it will return an InvalidOperationException.

Questo metodo è un' O(1) operazione.This method is an O(1) operation.

Si applica a

Vedi anche